"They're doing a variety of things, but a lot of them are basically interested in Eucalyptus for doing the same kinds of things they're doing in Amazon AWS, such as business logic applications, where part of the attraction of Eucalyptus is that they can use it as a platform for seamlessly running their public cloud applications and their on-premise cloud apps."
EUCALYPTUS - Elastic Utility Computing Architecture for Linking Your Programs To Useful Systems - is an open-source software infrastructure for implementing "cloud computing" on clusters. The current interface to EUCALYPTUS is compatible with Amazon's EC2 interface, but the infrastructure is designed to support multiple client-side interfaces. EUCALYPTUS is implemented using commonly available Linux tools and basic Web-service technologies making it easy to install and maintain.